Method for measuring acute stress in a mammal

ABSTRACT

A method is provided to quantify and/or qualify psychological and physiological components of stress in mammals, in which a stimulus can be applied to the test subject&#39;s environment during the test. The method involves the steps of measuring one or more physiological and/or psychological characteristics before and after the administration of a stimulus to a test subject. The stimulus may consist of any product, task, aroma or the like that elicits a stress-related response upon administration. By analyzing the resulting measurements, and optionally comparing physiological and psychological characteristics where both are measured, an overall level of stress may be determined. The method of stress measurement may further be used in product development and/or testing.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation in part of U.S. Non-provisionalapplication Ser. No. 10/405,378 filed on Apr. 02, 2003, which claims thebenefit of U.S. Provisional Application Ser. No. 60/369,678, filed Apr.3, 2002.

TECHNICAL FIELD

The present invention relates generally to stress measurementmethodologies. Specifically, the present invention is directed to amethod that allows for the rapid qualitative and quantitativemeasurement of the physiological and psychological effects of variousstimuli (e.g., aromas, products, tasks and other influences) on stress(e.g., emotions, moods, feelings) in mammals.

BACKGROUND OF THE INVENTION

Stress has been, and still is, a difficult thing to measure. Onedifficulty in measuring stress comes directly from the lack of a concisedefinition for stress. One definition of stress is: “Stress is the nonspecific response of the body to any demand.” (Hans Selye, “Stresswithout Distress,” published by Philadelphia: Lippincott, 1974.) Anotherdifficulty in measuring stress is in its diagnoses. Stress is difficultto diagnose because it reveals itself by a constellation of commonsymptoms with varying degrees of specificity. The sympstoms are afunction of: the stimulus (demand or pressure), their build up, as wellas the individual organism predisposition (weak links).

Examples of common “weak links” and the symptoms of their malfunctioninclude: (1) brain overstress: fatigue, aches and pains, crying spells,depression, anxiety attacks, insomnia, brain shrinkage; (2)gastrointestinal tract: ulcer, cramps and diarrhea, colitis, IBS,thyroid gland malfunction; (3) others: itchy skin rashes, decreaseresistance to infections, high blood pressure, heart attack, stroke,etc.

Another difficulty is the complexity of the human stress response.Stress has both psychological and physiological components; measuringonly one component is insufficient to provide a complete understanding.To measure stress, “mind and body” both have to be taken intoconsideration, as there is no psychological event without a resultingsomatic (bodily) event and vice versa. Stress response varies greatlybetween individuals. One person, for instance, may display large changesin electrodermal activity with increased stress and show only moderatechanges in heart rate and peripheral blood flow volume, while anotherindividual may show the reverse pattern.

Stress is rather ambiguous and ill-defined. There is no standarddefinition of stress and, consequently, there are no widely acceptedstandards for measuring stress. One reason for this is that everyperson's psychological and physiological response to stress is differentand can change over time. The magnitude of aromatheraputic effects isprobably small, making them difficult to isolate. There is muchscientific evidence that a person's physiological reaction to an odorantmay depend on their psychological response to the odorant, i.e., whetheror not the person likes the odor. Animal studies by Buchbauer indicatethat only specific varieties of essential oils—indeed, in some casesonly specific enantiomers of fragrance molecules—produce anaromatheraputic effect. This could explain some of the contradictoryfindings in the scientific literature regarding aromatherapy. A genericlavender, for instance, might not contain the correct amounts,proportions, or chemical species of the various components which areneeded to produce an effect.

In commonly assigned U.S. patent application Ser. No. 10/405,378 filedon Apr. 02, 2003, there is disclosed a methodology and apparatus fortesting and evaluating acute stress levels of human test subjects byacquiring both physiological and psychological information duringalternating periods of stress and relaxation. The methodology andapparatus disclosed therein also entail the acquisition of physiologicaland psychological information while subjecting the test subjects to astimulus, such as a fragrance, flavor, or product, or while the testsubjects are performing an activity or task. Further, the applicationdescribes the evaluation of acute stress levels of human test subjectsby acquiring physiological data from biosensors, such as EKG and bloodvolume pulse (BVP) sensors, and by acquiring psychological data fromquestionnaires.

A primary advantage of the invention disclosed in commonly assigned U.S.patent application Ser. No. 10/405,378 is that both psychological andphysiological measurements are simultaneously taken and assessed, whichprovides a much more accurate measure of a person's acute stress levelby taking into account both body and mind (body/mind) interactions. Themethods and apparatuses disclosed in said application can be used formany purposes, but at least provides certain scientific quantificationsof the psychological and physiological parameters, which have not beenavailable in the past testing or relaxation-determinative procedures.Another important aspect of the invention disclosed in commonly assignedU.S. patent application Ser. No. 10/405,378 is that the physiologicaland psychological factors are taken in a non-invasive manner, which is ahuge advantage as compared to taking blood, urine or saliva samples.

Despite having provided a substantial solution to contemporary issuesassociated with the measurement of an acute stress in a mammal via anassessment of psychological and physiological characteristics, thereremains a need in the art to identify an abbreviated method formeasuring acute stress in a mammalian subject. Such a method shouldfacilitate the rapid assessment of the level of acute stress in amammalian subject, with or without the use of computers or othercomputational tools.

SUMMARY OF THE INVENTION

The present invention addresses and resolves contemporary issuesassociated with stress measurement in a mammalian test subject byproviding a method by which acute stress may be rapidly assessed. Thus,in accordance with a first aspect of the present invention, a method ofdetermining relative stress level in a mammalian subject is provided.Said method comprising the steps of: determining a first (i.e.,baseline) physiological stress level of the subject; administering oneor more stimuli (e.g., product, task, aroma) to the subject, whereinsaid stimuli are intended to cause a change in the stress level of thesubject; determining a second physiological stress level of the subject;and comparing said first physiological stress level and said secondphysiological stress level to determine the stress level of the subject.In another aspect of the present invention, the above-mentioned step ofdetermining the stress level of a subject may be performed on a mammal.In another aspect of the present invention, the mammalian subject may beselected from the group consisting of: humans, cats, dogs, otherdomesticated animals and combinations thereof. In a particularlypreferred aspect of the present invention, the level of stress in amammalian subject may be assessed via measurement of one or morephysiological characteristics of the mammalian test subject underconsideration. As will be described more thoroughly hereinafter, saidphysiological characteristics may include, yet are not limited to: heartperiod, pulse transit time, peripheral blood flow, standard deviation ofnormal to normal beats (SDNN) and combinations thereof. In yet anotheraspect of the present invention, the level of stress in the mammaliansubject may be assessed via the measurement of one or more psychologicalcharacteristics.

In one aspect of the present invention, one or more psychologicalcharacteristics of the mammalian subject under consideration may bemeasured via the administration of a questionnaire to said subject,wherein one or more answers to questions from said questionnaire aredesigned to evaluate at least one psychological component of acutestress. Suitable questionnaires for purposes of the present inventioninclude those which may be administered to the mammalian subject underconsideration in a rapid manner to facilitate the swift assessment ofthe overall level of stress in said mammalian subject. In yet stillother aspects of the present invention, the level of acute stress in amammalian test subject may be assessed via measurement of one or morephysiological characteristics and one or more psychologicalcharacteristics, the combination of which may be analyzed to determinean overall level of stress in said mammalian subject, as described morefully hereinafter.

One advantage of the present invention is that the acute stress level ofa mammalian subject may be assessed in a swift and accurate manner.Those skilled in the art to which the subject invention pertains willappreciate that the level of acute stress in a mammal is subject torapid change, and thus, instantaneous measurement is requisite to theprovision of meaningful stress level results for any given moment. Themethods of the present invention are designed to quickly facilitate themeasurement of acute stress in a mammalian subject, and thus, providethe practitioner of the present methods with measurements that moreaccurately reflect the level of stress in a mammal at the moment atwhich measurement of stress is intended. The accuracy of the methodsdisclosed herein is further bolstered via the simultaneous measurementof both psychological and physiological characteristics of a mammaliansubject. Of course, another important aspect of the present invention isthat the level of acute stress in a mammalian subject is measured in anon-invasive manner (particularly in comparison to blood, urine orsaliva samples), thereby increasing the likelihood that a mammaliansubject will subject themselves to administration of the present methods(particularly for consumer research purposes).

Still other advantages of the present invention will become apparent tothose skilled in the art to which the present invention pertains fromthe following description wherein there is described and shown apreferred embodiment of this invention in one of the best modescontemplated for carrying out the invention. As will be realized, theinvention is capable of other different embodiments, and its severaldetails are capable of modification in various, obvious aspects allwithout departing from the invention. Accordingly, the descriptions willbe regarded as illustrative in nature and not as restrictive.

All documents cited are, in relevant part, incorporated herein byreference; the citation of any document is not to be construed as anadmission that it is prior art with respect to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Definitions

As used herein, the term “fragrance” is intended to refer to a type of“stimulus” that could either be relaxing or stimulating, or perhapscould have no perceivable effect on a person. The terms “fragrance” or“stimulus” can be interchanged in most cases, with respect to theprinciples of the present invention. Furthermore, the term “fragrance”can literally represent an actual fragrance (e.g., in a liquid state) oran odor (e.g., in a gaseous state), or the term “fragrance” canrepresent a flavor (such as in a beverage). The term “fragrance” canalso represent essential oils, an aroma or scent. A “fragrance” can besubliminal (at a concentration too low to be consciously detected by ahuman) or non-subliminal (at a concentration high enough to beconsciously detected by a human). Finally, the terms “fragrance” or“stimulus” can alternatively represent some type of “product” or couldrepresent a “task.”

As used herein, the term “stimulus” is intended to refer to any type ofobject, product or task that appeals to any of the five senses (e.g.,smell, touch, hearing, taste, sight). In the case of an object orproduct, a stimulus may include an aroma or an essential oil, amongothers.

In the case of a “product,” the terms fragrance/stimulus could representa perfume or a cologne, for example, or some other complex formulation(e.g., a mixture of two or more perfumes); or some type of therapeuticdevice or medical device, for example, such as hot towels, orchemically-activated heat-releasing wraps such as those under theregistered trademark THERMACARE® heat wraps, owned by The Procter &Gamble Company.

In the case of a “task,” the terms fragrance/stimulus could representsome activity that may be relaxing, such as a person taking a hotshower, or cleaning, or washing dishes or clothing, ironing, orperforming some other ergonometrically-designed tasks to relieve stress.Further details of some of these examples are discussed below.

The term “product” is intended to refer to, among others, one or morebeauty and/or hair care products such as soaps, shower gels, shampoo,conditioners, personal cleansing; fine fragrances or colognes; home careproducts, such as dishwashing products, air fresheners, softeners,tissues, and towels; baby care products, such as diapers, and wipes;feminine care products, such as PMS products, or products for menopause.Other products could also include over the counter items, such astoothpaste, VAPO-RUB® ointment, and cough syrups. Particularly preferredproducts for purposes of the present invention include those marketed byThe Procter and Gamble Company of Cincinnati, Ohio.

The terms “subject,” “test subject,” “mammalian subject,” and “mammaliantest subject” are intended to refer to a mammal to which the methods ofthe present invention may be administered to elicit a meaningful,stress-related measurement. Suitable mammals for use in the context ofthe present invention include: humans and domesticated animals, such ascats and dogs.

First Aspect: Method of Determining Relative Stress in a Subject

In accordance with a first aspect of the present invention, a method ofdetermining relative stress level in a subject is provided. Said methodcomprises the steps of: determining a first (i.e., baseline)physiological stress level of the subject; administering one or morestimuli (e.g., product, task, aroma) to the test subject, wherein saidstimulus is intended to cause a change in the stress level of thesubject; determining a second physiological stress level of the subject;and comparing said first physiological stress level and said secondphysiological stress level to measure the overall stress level of thetest subject.

In accordance with this aspect of the present invention, a firstphysiological stress level of the test subject may be determined bymeasuring one or more physiological characteristics of the subject(described infra). In another aspect of the present invention, the firstphysiological stress level may be measured by using the stressmeasurement apparatus disclosed in commonly-assigned U.S. ProvisionalApplication Ser. No. 60/369,678, filed Apr. 3, 2002. As will bedescribed more thoroughly hereinafter, said physiologicalcharacteristics may include, yet are not limited to: heart period, pulsetransit time, peripheral blood flow, standard deviation of normal tonormal beats (SDNN) and combinations thereof.

Upon determining the first physiological stress level of the subject, astimulus (e.g., product, task or aroma) may be administered to the testsubject. As described in the “Definitions” section of the presentdisclosure, the term “product” for purposes of the present invention isintended to encompass any product, commercial other otherwise, thatcauses any perceivable change in the stress level of a test subject.Particularly preferred products for purposes of the present inventioninclude those that appeal to the senses of smell (e.g., perfumes,colognes, aromas) and touch (i.e., hot towels, heating pads). In anotheraspect of the present invention, particularly preferred products forpurposes of the present invention include those marketed by The Procterand Gamble Company of Cincinnati, Ohio, as well as products marketed byothers that are part of the same product category as those productsmarketed by The Procter and Gamble Company.

In yet still another aspect of the present invention, the stimulusadministered to the test subject may include a task. Indeed, the testsubject may engage in the completion of a task following measurement ofthe first physiological stress level of the subject. As described in the“Definitions” section of the present disclosure, the term task isintended to refer to virtually any task that elicits a stress-relatedresponse in a test subject. Tasks suitable for use in the context of thepresent invention include, without limitation, relaxation and/orcleaning. In one aspect of the present invention, the acute stress levelof a mammalian subject may be ascertained while said subject isperforming a task selected from the group consisting of taking a shower,cleaning, washing dishes, washing clothing, ironing clothing and otherhousehold-related activities. In yet still another aspect of the presentinvention, a test subject may be subjected to the use a product and thecompletion of a task simultaneously, upon measurement of the firstphysiological stress level. In one aspect of the present invention thetask for which completion is intended during use of the product mayindeed be associated with the intended use of the product. For example,a test subject may use a product such as the Swiffer Wet Jet™floor-cleaning device, marketed by The Procter and Gamble Company ofCincinnati, Ohio, to engage in a task such as cleaning a kitchen floor.While physical tasks may, in and of themselves, be relaxing orstressful, with the present invention it is nevertheless possible toalso determine if a fragrance (or “stimulus”) adds or subtracts anyfurther component of relaxation to a person's acute stress state.

In yet still another aspect of the present invention, the stimulus ofthe present invention may be characterized based on the level ofexertion associated with administration to the test subject. Forexample, a stimulus such as a product, fragrance or aroma, theadministration of which requires little to exertion on the part of thetest subject may be characterized as a “passive stimulus.” Conversely, astimulus such as an activity or task, the administration of whichrequires active exertion and/or effort on the part of the test subjectmay be characterized as an “active stimulus.” The methods of the presentinvention seek to encompass the measurement of stress following theadministration of virtually any stimulus, whether passive, active orboth.

Upon administering one or more stimuli to the test subject, a secondphysiological stress level may be measured. The second physiologicalstress level may be similarly assessed by measuring one or morephysiological characteristics, as described hereinafter. Uponascertaining both the first (baseline) and second physiological stresslevels, a comparison may be made between the two levels to provide anoverall assessment of the level of stress of the test subject followingadministration of the product. In one aspect of the present invention,the first and second stress levels are simply compared to determine therelative change in stress level following the administration of one ormore stimuli. In another aspect of the present invention, the first andsecond physiological stress levels are compared by assigning a numericalvalue to each of the overall physiological and psychologicalmeasurements. In one aspect of the present invention, the same methodmay be used to assign quantitative values to the both the physiologicaland psychological measurements such that the two measurements may beaccurately compared. In another aspect of the present invention, theindividual numerical values for each of the physiological andpsychological characteristics may be merged into a single numericalvalue to provide an overall quantitative assessment of both thephysiological and psychological characteristics of the test subject. Inone aspect of the present invention, the overall numerical valueassigned to the combined physiological and psychological characteristicsmay be assigned a qualitative label based on the overall numericalvalue. For example, a product may be assigned a qualitative label of“Strongly Relaxing” if the ratio of the physiological and psychologicalcharacteristics is between 0.0 and 0.5. The term “ratio” is intended torefer to the absolute ratio between a given physiological characteristicand a psychological characteristic. The term “ratio” is also intended torefer to the level of change in a given physiological or psychologicalcharacteristic upon being exposed to a stimulus, in which case the ratiomay be the level of stress in the subject prior to administration of astimulus over the level of stress following administration of thestimulus. In yet another aspect of the present invention, a mathematicalfunction that merges the individual physiological and psychologicalcharacteristics into a single number may be used to provide an overallassessment of the level of acute stress in the test subject underconsideration. Non-limiting examples of mathematical functions suitablefor use in the context of the present invention include regressionanalysis, among others.

Suitable physiological characteristics suitable for quantifying stressin the context of the present invention, include but certainly are notlimited to heart period, pulse transit time, peripheral blood flow,standard deviation of normal to normal beats (SDNN) and combinationsthereof. In yet another aspect of the present invention, othernon-invasive measurements could be used in addition to, or in lieu of,one or more of the above parameters. Other non-invasive measurements mayinclude, but certainly are not limited to muscle relaxation, skintemperature, skin conductivity measurements, pupil dilation, salivaryflow, capillary dilation, bronchi constriction, stomach motility andcombinations thereof.

With regard to the above-noted four physiological measures, the “heartperiod” is the length of time between heartbeats, which is the inverseof the heart rate. An increase in heart period generally means areduction in stress. The “pulse transit time” is the amount of time ittakes for a bolus of blood squeezed from the heart to reach thefingertip; it is an inverse analog of blood pressure. An increase inpulse transit time generally means a reduction in stress. The“peripheral blood flow” is a measure of how much blood is flowing incapillaries near the surface of the skin. When a person is under stress,the sympathetic nervous system constricts the capillaries in the skin toshunt blood to the muscles in preparation for fight or flight. Anincrease in peripheral blood flow generally means a reduction in stress.The SDNN is a measurement of heart rate variability, and is the standarddeviation of the period of time between two normal heartbeats. Mostpersons believe that the human heart beats at a steady pace (underconstant workload); however, the time between beats for a healthy heartwill vary quite a bit (in the range of milliseconds for the variations).When under stress, the variation decreases; thus an increase in SDNNgenerally means a reduction in stress.

In yet another aspect of the present invention, the level of stress inthe mammalian subject may be assessed via the measurement of one or morepsychological characteristics of the mammalian test subject. Indeed, inone aspect of the present invention, a one or more psychologicalcharacteristics of the mammalian test subject are measured via theadministration of a questionnaire to said subject, wherein one or moreanswers to questions from said questionnaire are designed to evaluate atleast one psychological characteristic. Any suitable questionnaire maybe administered in accordance with the present invention. Suitablequestionnaires include The Mood Adjective Check List (MACL) of theUniversity of Wales Institute of Science and Technology; the abbreviatedMehrabian PAD scale; and Desmet's PREMO instrument. Particularlypreferred questionnaires for purposes of the present invention includethose which may be administered in less than five minutes, preferablyless than two minutes, more preferably less than one minute, mostpreferably 20 seconds. Suitable questionnaires for use in the context ofthe present invention may be provided in both oral and/or written form.Other questionnaires suitable for use in the context of the presentinvention are described in the following references: (1) Matthews,Gerald, Dylan M. Jones, and A. Graham Chamberlain. Refining theMeasurment of Mood: The UWIST Mood Adjective Checklist. British Journalof Psychology, 1990, Vol. 81, pp. 17-42; (2) Mehrabian, Albert.Framework for a Comprehensive Description and Measurment of EmotionalStates. Genetic, Social, and General Psychology Monographs, 1995, Vol.121 (3), pp. 339-361; and (3) Desmet, Pieter. Designing Emotions. PhDDissertation 2002, Technical University of Delft, Netherlands.

Second Aspect: Method of Developing Product, Task and/or Aroma

In yet another aspect of the present invention, a method for evaluatingand/or developing a stimulus (e.g., product, task, aroma) is provided.In one aspect of the present invention, said method comprises the stepof using the method disclosed in the First Aspect of the presentdisclosure to further develop and/or evaluate a product, task or aromato which the test subject is exposed. In one aspect of the presentinvention, the psychological and/or physiological measurements obtainedfrom one or more test subjects upon being exposed to the same product,task or aroma are compared to subsequent measurements to determine theoverall level of stress related to administration of the product task oraroma to the test subjects. In another aspect of the present invention,one or more of the characteristics of a product, task, aroma or otherstimulus may be modified and/or altered upon measurement of stressfollowing its administration to one or more test subjects, to elicit adesired stress-related response. For example, if a qualitativestress-related response of “relaxing” is desired and a fragrance is usedto elicit a stress-related response, then the composition orconcentration of a fragrance may be altered accordingly. Those skilledin the art to which the present invention relates will appreciate thatthe precise adjustment or alteration made to the product, task or aromawill depend upon several factors, including, but not limited to: thenature of the stimulus under consideration and the needs and/orabilities of the practitioner.

EXAMPLES Example 1 Fragrance Administration

The Aroma Therapy Stress Measurement Protocol (or ASMP) experiment isdesigned to test three fragrances and one control (e.g., water). Theblank is usually considered essential, because it provides the baselinestress/relaxation response that the fragrances will be compared to. Thefragrances should be diluted to a strength that is appropriate to thepurpose of the experiment and, if possible, to similar perceivedstrengths. If an olfactometer is available, it can be used to administerthe fragrances. Otherwise, the fragrances can be presented to the testsubject by saturating equal-sized strips of filter paper with thefragrance and placing the filter paper in an open wide-mouth jar placedapproximately 30 centimeters from and level with the test subject'schin. The room in which the experiment is conducted should be designedfor high air turnover (at least eight complete air changes per hour isrecommended) or, at a minimum, have a fume hood.

Example 2 Assignation of Qualitative Labels to Stress Measurements

Qualitative labels may be assigned to both the stress measurementsobtained using the method of the present invention. In qualitativelyanalyzing a measurement, for example the measurement of a physiologicalcharacteristic, a qualitative label may be assigned to the measuredstress level depending upon the ratio of the first stress measurementand second stress measurement. Namely, if a first stress measurement,for example peripheral blood flow, was determined to be 0.42 and asecond stress measurement was determined to be 0.84, then a qualitativelabel of “Strongly Relaxing” may be assigned to the measurement.Assignation of qualitative labels for combined measurements may be donein accordance with the following table:

Ratio of First Physiological Stress Measurement and Second PhysiologicalStress Combined Qualitative Measurement Label Assigned 0.0 < ratio < 0.5Strongly relaxing 0.5 < ratio < 0.9 Relaxing 0.9 < ratio < 1.0 Mildlyrelaxing 1.0 No effect 1.0 < ratio < 1.1 Mildly stimulating 1.1 < ratio< 1.5 Stimulating Ratio >= 1.5 Strongly stimulating

Example 3 Quantitative Analysis of Stress Measurements

The physiological and psychological measurements obtained via practiceof the methods disclosed herein may be combined and reported as asingle, quantitative value. Administration of the psychologicalquestionnaires generates a set of N numbers that describe a person'smood or emotional state. The physiological measurement(s) made duringperformance of the methods of the present disclosure generate a separateset of M numbers. The combined psychological and physiologicalmeasurements form an N+M dimensional space that must be reduced to asingle value. A mathematical function is created that combines the N+Minputs into a single number indicating stress level. Such a functioncould be created by a regression analysis of experimental data.

Example 4 Performance of the Present Methods using only PhysiologicalCharacteristics

The method of the present invention was performed employing onlyperipheral blood flow as the physiological measurement. The peripheralblood flow of each test subject was measured prior to administration ofa stimulus. Then, a lavender-based stimulus was administered to eachsubject for a period of 20 seconds. Separately, the peripheral bloodflow of each test subject was measured prior to the administration of anherbal-based stimulus. The herbal stimulus was then administered to eachsubject for a period of 20 seconds. Based upon application of the ratiosto the table listed in Example 2 of the present disclosure, it wasdetermined that the lavender fragrance is relaxing to test subjects andthe herbal fragrance is stimulating.

Subject Lavender Ratio Herbal Ratio 1 0.58 1.08 2 0.96 1.30 3 0.89 1.094 0.90 1.22

Example 5 Development of Product Using Present Methods

A laundry group seeks to create a detergent with a relaxing scent thatis adapted to promote restful sleep when used on bedding. Threecandidate fragrances are developed and tested with the methods of thepresent invention to determine which is the most relaxing. Threedifferent fragrances are each administered to forty test subjects. Theaverages of the peripheral blood flow ratios for each fragrance are0.84, 0.67, and 1.03, respectively. The second fragrance, with anaverage ratio of 0.67, is the most relaxing of the fragrances. Thelaundry group decides to use Fragrance Number 2 in the subject laundrydetergent.

The foregoing description of a preferred embodiment of the invention hasbeen presented for purposes of illustration and description. It is notintended to be exhaustive or to limit the invention to the precise formdisclosed. Obvious modifications or variations are possible in light ofthe above teachings. The embodiment was chosen and described in order tobest illustrate the principles of the invention and its practicalapplication to thereby enable one of ordinary skill in the art to bestutilize the invention in various embodiments and with variousmodifications as are suited to the particular use contemplated. It isintended that the scope of the invention be defined by the claimsappended hereto.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

1. A method of determining relative stress level in a subject, saidmethod comprising the steps of: determining a first physiological stresslevel of the subject; administering a stimulus to the subject, whereinsaid stimulus is intended to cause a change in the stress level of thesubject; determining a second physiological stress level of the subjectby measuring the physiological characteristics selected from the groupconsisting of heart rate, pulse transit time, peripheral blood flow,SDNN, skin temperature, skin conductivity, pupil dilation, salivaryflow, capillary dilation, bronchi constriction, stomach motility andmixtures thereof of said subject within about 10 seconds to about 120seconds of administration of said stimulus; and comparing said firstphysiological stress level and said second physiological stress level todetermine the change in stress level of the subject.
 2. The methodaccording to claim 1, further wherein said first and second stresslevels are psychological stress levels.
 3. A method according to claim1, wherein the steps of determining the stress level of a subject areperformed on a human subject.
 4. A method according to claim 2, whereinsaid step of measuring said stress level comprises the administration ofa questionnaire to said subject, wherein one or more answers toquestions from said questionnaire are designed to evaluate at least onepsychological component of acute stress.
 5. The method according toclaim 4, wherein: said questionnaire comprises a plurality ofquick-answer questions that provide a measure of perceived physiologicaleffects of acute stress.
 6. The method as recited in claim 5, wherein:answers to said quick-answer questions provide a measure of the testsubjects psychological state.
 7. A method according to claim 1, whereinsaid stimulus is selected from the group consisting of: products,commercial products, tasks, tasks relating to the use of a product,aromas and combinations thereof.
 8. A method according to claim 7,wherein said product is selected from the group consisting of consumerproducts, fragrances, aromas, scents, odors, flavors, therapeuticdevices, cough syrups, inhalants, toothpastes, lozenges, dental flossand combinations thereof.
 9. A method of determining the stress of asubject according to claim 1, wherein the steps of determining saidstress is performed in a setting selected from the group consisting of:home setting, retail setting and combinations thereof.